Home & DIY Calculators
9 tools
Home projects usually go wrong on quantities: too little paint, an AC unit that’s too small, a gutter that overflows in the first storm. Put in the size of the room or roof and these calculators tell you what to buy or compare, from tile and thinset to BTUs, kWh and solar panels. Treat the answers as a solid starting point and ask a pro before anything structural or electrical.
Tools in this category
AC BTU Calculator
Estimate the cooling capacity (BTU) your room needs from its area, sun exposure and heat-producing appliancesAppliance Energy Use Calculator (kWh)
See how many kWh any appliance uses per day, month and year, and what it costsConcrete Mix Ratio Calculator
Calculate bags of cement, sand, gravel and water for any concrete mix ratio, with buckets and mixer batchesGutter Size & Downspout Capacity Calculator
Calculate roof runoff flow rate, recommended gutter width, and downspout dimensionsInverter vs Conventional AC Payback Calculator
Find out if an inverter air conditioner is worth the extra cost: yearly energy savings and payback timePaint Coverage & Gallon Calculator
Work out how much paint and how many cans you need, with doors, windows and coats taken into accountSolar Panel Calculator
Estimate how many solar panels you need, the system size in kW and the roof area, based on your monthly electricity useThinset & Grout Calculator
Calculate tile adhesive and grout in kg and bags from tile size, joint width and trowel notchTile & Grout Calculator
Work out how many tiles you need, the area with a waste margin and the estimated cost